A.5.292 SHUFPD: Shuffle Packed Double-Precision FP Values
SHUFPD xmm1,xmm2/m128,imm8 ; 66 0F C6 /r ib [WILLAMETTE,SSE2]
SHUFPD moves one of the packed double-precision FP values from the
destination operand into the low quadword of the destination operand;
the upper quadword is generated by moving one of the double-precision
FP values from the source operand into the destination. The select
(third) operand selects which of the values are moved to the destination
register.
The select operand is an 8-bit immediate: bit 0 selects which value is
moved from the destination operand to the result (where 0 selects the
low quadword and 1 selects the high quadword) and bit 1 selects which
value is moved from the source operand to the result. Bits 2 through 7
of the shuffle operand are reserved.